I wrote this mainly to talk about ADV as I see it right now. Over the last year I’ve seen it both become more rigid, as well as certain anti-meta picks like Heracross, Moltres become more popular than perhaps at any other time.
To understand my perspective on the tier, it’s necessary to both note I’ve been playing for around a year by this point so most of my opinion is colored by post rest-talk mech changes ADV as opposed to before it.
A lot has changed, ADV feels very offensive right now to me, and the prominence of spikes exacerbates that. I feel like in spite of being quite old, a lot of team that did stuff like rely heavily on Rest Snorlax/Rest Suicune are becoming more and more unviable and difficult to get going without focusing an entire build and an almost mandatory support cast around them.
Defensive Suicune ironically can't be used as a bulky water at all,it is the one water that little support to the team in terms of switching into like CB Meteor Mash or CB Rock Slides from Gross/Tar; the best teams for defensive Suicune are probably Magneton+Claydol(possibly even wants Dugtrio+Rain Dance) teams, if only because even 1 layer of spikes with Sand down, means more likely than not Suicune will just be Resting all game; it's like Snorlax in that it is really spikes vulnerable, and hard to get going under sand. There's a reason why most teams still opt for Swampert(one of the best pivots in the game), instead of the more dangerous(on paper) Suicune.

Even teams that on paper have no real Rest CM Cune check, can beat it via rest looping, with stuff like CB Aerodactyl coming in on the rest turn under sand.If you have to talk of the most effective Suicune set, to me its probably still just offensive CM; but that set is prone to getting Toxic traded on it via Swampert/Skarmory/etc. Set with the most potential upside as stated above is defenitely SubCM, that set under sand though probably has only one good chance to sweep per game, although versus teams that have stuff that it abuses like Leech Celebi or IB+Fire Blast+Toxic Blissey it has chances to get very easy setup/sweeps. More traditional offensive Suicune sets, probably want stuff like Boom Regice/Boom Gengar+Dugtrio to create openings for it
Snorlax is kind of Suicune in that its most dangerous set, requires Magneton, and rapid spin support. Other sets like mixlax have steadily become less and less effective, Curse+Boom isn't as effective at trading with Skarmory as it used to be; my gripe with MixLax especially is that unless you catch Gengar on a switch with Shadow Ball, you're really just gonna get will-o-wisp'ed and basically be carrying dead weight. I also don't like how Zapdos under sand(especially if its not rest Zap), basically hurries MixLax into self-destructing much quicker than it'd like. Mixlax is usually thrown on to more physically oriented teams as a sponge but vs stuff like Zap/+1 Offensive Cune Hydro with sand, it really is just a whole slot dedicated to trading with boom.
In a tier centralized around spikes its only natural that controlling and abusing them became very central to how it operates. I've always thought that Gengar is the best pokemon at abusing spikes, . stuff like HP:Grass Gar becoming more popular has helped it counteract the trend of Pursuit Tyranitar being everywhere, while also letting it kill Swampert without having to eat Torrent Hydro Pump from higher ranges. Hypnosis is also amazing at cheesing teams right now, especially if you get the chance to use Hypnosis as Pursuit Tar comes in(even better with Spikes down) there are teams that you might just clean from that point on, which frankly is pretty ridiculous. Add to that the fact bulky gar takes a CB Aerodactyl Rock Slide(quite comfortably actually), and if running 252 HP/112 sp.def(Taunt+WoW with this is brutal) can switch out of a tyranitar's Pursuit in order to trap it with Dugtrio, and that only adds to the package. Gar with spikes down and Hypnosis or Taunt/WoW can also severely pressure Blissey(can just boom on it too I guess), great mon. The best thing about Gengar is that its stat spread is JUST good enough to both provide defensive utility as well as offensive presence
Skarmory is the best spiker, and a key defensive component as well on many teams; Skarmory between itself, bulky gengar and tyranitar can maintain hazards vs any team, and this is big reason why this is hands down the engine room of any TSS used in ADV atm. Want to mention that bulky mie without Magneton isn't very good at keeping hazards off, and that offensive mie is still the best set. The fact that it can spin on that(one time a game probably) is a bonus. Heck on certain teams(BKC's famous Cele Skarm Mag comes to mind) even WITH a magneton on the other side, you can potentially set up a situation to end up with three layers, which is kind of crazy frankly.
Tyranitar has evolved too, the flagship Taunt+Dragon Dance while still good is nowhere near as common as before, with mixed/special variants being the most popular which makes sense considering how Will-o-Wisp Gengar is always right around the corner. This is not to say that DD variants can’t be good: all of Taunt/Ice Beam/Toxic/HP:Grass have their place on it. Special Tyranitar+Forretress is quite a popular core, but I can’t help but mention that Forretress in a Gengar oriented metagame is quite possibly at its lowest. It still has value on double spiker outfits(which generally consist of Skarmory+Dugtrio+Forretress), but as the stand alone Spiker its much worse, which is definitely a fall from grace for the spiker on the metagame defining stall made by Tamahome many years ago(Tyranitar/Celebi/Swampert/Gengar/Blissey/Forretress).
Status spread also defines ADV at the moment so a number of Refresh users recently became much more popular in the form of Claydol and Milotic. Refresh Milotic especially can be frustrating to play against for teams relying on a low health bulky water to open up a chance for a potential DD Tyranitar or DD Salamence sweep. A lot of teams slowly but steadily lose to Toxic being spread amongst its members, and its only gotten worse because Heal Bell/Aromatherapy are very rarely seen on Celebi or Blissey right now. A popular strategy that’s emerged is using Magneton to remove Skarmory, to force bulky waters to accept Toxic.
When talking about spikes, its only fair to also mention how it should be taken on. There are a number of philosophies on tackling it, ranging from tacking on a Magneton, to running Magneton+a spinner, to running multiple Taunt users, to running teams with multiple flyers or levitators, to running spikes less offenses. But whatever you do, you need a plan to tackle them.
Ironically even though the tier is more offensive right now due to Gengar/Spikes, Heracross has emerged as a deadly counterpick and certain teams are 6-0’d by the popular SD/Focus Punch set, you’ll frequently see teams with configurations like Tyranitar/Skarmory/Swampert/x/Blissey/Gengar, that really have no practical outs in some cases depending on the x filler and the Gengar set. The rarity of Drill Peck on Skarmory makes this worse. Keeping proper switch patterns, and not falling into bad habits are crucial to succeed vs it. Jolly is generally the nature of choice on Heracross right now, rendering things hovering around the 270 speed region a lot less safe vs Heracross than before.
Moltres has emerged as a solid pick and is an excellent filler for the 6th slot in TSS. It is an excellent way to abuse spikes and even running Blissey doesn’t necessarily mean that you’re secure versus it. When three layers are in play, Fire Blast is doing 25%, sand is up, and your opponent has physical options to double into versus Blissey you’ll often feel your options vs Moltres be choked off as you head into the end game.
Jirachi again has changed a lot, recently sets such as Toxic/Fire Punch/Wish/Protect and Fire Punch/Body Slam/Wish/Protect have emerged as excellent support with the first set being able to sit on Flygon and Swampert easily and force Toxic on to them, making late game Aerodactyl and Tyranitar far more dangerous. And the second sitting on most special attackers easily, both provide reliable Wish support which is great when Spikes are in play. Mixed Jirachi while not “new” in the sense that Toxic/Fire Punch is, is still vicious vs standard teams solely due to the coverage it has, while Superrachi(CM+3 attacks). Wish +Calm Mind+Psychic+Thunderbolt/HP:Grass/Fire Punch is still extremely threatening for bulky teams, and teams without Thunder Wave Blissey can sometimes be hard pressed to stop it, once it gets rolling. Overall Jirachi has become much more notable than it was before, and is probably the best out of the CM trio of Suicune/Celebi and itself.
Raikou usage has tremendously decreased, which makes sense considering how much CM Spam has declined. The mainly issue for the style is that it just does not pose an offensive threat anymore, and people have learned how to play against the style much better than before. That in conjunction with more offensive teams being common led to CM Spam being a shaky choice in general at the moment. Raikou as a result is a bit of a remnant of the past, which to an extent has led to Adamant Dugtrio becoming a bit more popular. Jolly Dugtrio obviously is still very good though, with offensive Starmie being one of the notable threats it picks up.
Swampert and Celebi are still key defensive pieces(while still possessing very good offensive sets in Endeavor Swampert, and offensive 3 attacks CM Celebi and SD/CM Baton Pass) but it has to be noted that they are very prone to giving up momentum and providing opportunity for spikes to be setup, so on more defensive teams it is not out of the place to see Magneton paired with them, Celebi being an especially good partner thanks to Baton Pass. Leech Seed/HP:Grass or Psychic/CM/Recover used to be the most popular but right now the Substitute/Leech Seed/Recover/Baton Pass set, and Leech Seed/Psychic/HP:Grass/Recover are trending.
Even Salamence has changed a bit with offensive Wish(unveiled by BKC in 2015) seeing use here and there, with Mixed Salamence still being the most popular set. Dragon Dance Salamence+Magneton however is still very potent and not to be underestimated, its still a vicious cleaner.
Metagross has also gotten a lot better over the past year, whether it be sets like Toxic(Toxic/EQ/Meteor Mash/Explosion or the notorious Toxic/Protect/Meteor Mash/EQ or Explosion) or Mixed Metagross and Choice Band Metagross. Mixed Metagross in particular with Psychic/HP:Fire is very anti-metagame and pries a lot of defensive teams open.
Aerodactyl has also started running different Hidden Powers in Bug/Fighting, which help in simplifying certain end games. Bug in particular has become quite popular and let’s you pick up Celebi, while being covered against Tyranitar in the late game.
Even something traditionally defensive as Blissey has changed with Fire Blast/Ice Beam/Toxic/Softboiled emerging as the most popular set thanks to UD. This set is another way top players are adapting to spikes becoming more rampant. Calm Mind Blissey has fallen off quite a bit, which actually is a key reason for Substitute Suciune being in vogue again.
Zapdos has also changed, with Rest sets finding their place on defensive sand teams, occasionally packing stuff like Heal Bell Celebi or Aromatherapy Blissey to help it wake up. Offensive Zapdos is a bit slept on right now, and skimping on a way to play around 383 special attack Thunderbolts is something you should do at your own peril.
I think this cover for the most part changes in the major players themselves and how the tier is played.
After this the most relevant thing to discuss is probably the broad playstyles in the tier.
Bulky Setup (Ex: Curselax/Cune):
These team hate spikes, and frequently will feature Magneton+Claydol to ensure that Snorlax and/or Suicune have to deal with the least residual damage possible. Sometimes you even see them run Dugtrio(sometimes Sunny Day) and/or Rain Dance on either of Zapdos or Claydol to remove even sand. An example of a team like this that’s popular might be Suicune/Snorlax/Claydol/Magneton/Celebi/Dugtrio.
Skarm-Mag:
The most popular variant of SkarmMag belongs to BKC, Celebi/Skarmory/Swampert/Tyranitar/Aerodactyl/Magneton. The team plays in a very straightforward manner with Magneton(sometimes with Magnet) meaning you usually have 3 layers out as opposed to the opponents 1 or 2, which makes the Aerodactyl in back far more dangerous
special spikes offense (ex jolteon):
Jolteon/Skarmory/Aerodactyl/Swampert/Gengar/Tyranitar is probably the flagship team people associate with this play style. Together Aerodactyl/Gengar/Jolteon with Spikes in play provide you multiple avenues with which to abuse Spikes, the Gengar is frequently an Explosion set, to make it easier for Jolteon to clean up. As for the Tyranitar set both DD and CB have seen use on that particular configuration.
CM Spam:
The original one made by JabbaTheGriffin was Suicune/Celebi/Jirachi/Dugtrio/Swampert/Tyranitar, but is probably not the most popular one right now. More modern ones frequently see Porygon2 used as well and frequently run stuff like Hypnosis/Explosion Gengar or Explosion Regice to help Dugtrio in removing Blissey. In 2017 these teams perhaps provide far less offensive threat then they used to, and have seem a significant reduction in usage
Physical Spam:
Tyranitar/Metagross/Snorlax/Aerodactyl/Heracross/Swampert, is an example of a typical team of this archetype. They generally look to remove Swampert or other bulky water either by forcing Toxic on to them, or by Exploding on them, letting one of the other members in Tyranitar or Aerodactly potentially end the game.
TSS:
Broadly this is Tyranitar/Skarmory/Blissey/Gengar/Swampert/x. Perhaps the most common configuration seen in ADV with minor tweaks(sometimes Forretress>Skarmory, generally results in a more defensive team). MDragon’s famous variant of this runs Aerodactyl in the x spot, while UD is partial to Starmie as the filler on that. The team thrives on either chipping everything into range of an Aerodactyl clean, or in the case of the offensive Starmie variant looks to Explode on Blissey and keep Starmie in hand to end the game.
Mixed Spikesless Offense (ex mixxlax + Zapdos):
Zapdos/Snorlax/Metagross/Salamence/Swampert/Celebi is an example of this kind of team. These teams are generally quite flexible, and feature multiple ways to pressure Skarmory, a bulky pivot to rocks generally in the form of Swampert, multiple explosions, and ways to close out a game in stuff DD Tyranitar/DD Salamence/CB Aerodactyl.
There’s always something changing,something shifting with respect to even a “static” generation like ADV. I’m looking forward to watching what changes SPL 2018 brings to the tier, and want to see the game being pushed forward more.
I hope to update this eventually as 2017 rolls into 2018.